For the chocolate cake
25g/1oz cocoa powder, plus extra for dusting
3 tbsp boiling water
100g/3 oz caster sugar
100g/3 oz self-raising flour
1 level tsp baking powder
2 large free-range eggs
100g/3 oz margarine, plus extra for greasing
2 tbsp brandy
For the mousse
300g/11oz plain chocolate (no more than 40-50 per cent cocoa solids), broken
into squares
450ml/16fl oz whipping cream
To serve
225g/8oz fresh raspberries and blueberries
double cream
icing sugar, for dusting
Method
Preheat the oven to 180C/160C Fan/Gas 4. Grease the tin with margarine and line
the base and sides with baking paper. You need to line the tin right to the top
even though the sponge will not fill it.
For the chocolate cake, measure the cocoa powder into a large bowl. Pour over
the boiling water and mix to a paste with a spatula. Add the rest of the dry
ingredients and the eggs and margarine and beat until smooth using a hand-held
mixer.
Spoon the cake mixture into the prepared cake tin and level the surface with a
palette knife. Bake in the oven for 20-25 minutes, or until a skewer inserted
into the centre of the cake comes out clean and the cake feels springy to the
touch.
While the cake is still hot, brush the brandy over the top of the cake. Leave
the cake to cool in the tin.
Meanwhile, for the mousse, place the chocolate in a bowl and melt over a pan of
gently simmering water (do not allow the base of the bowl to touch the water).
Stir continuously, taking care not to let the chocolate get too hot. Set aside
to cool a little.
Whip the cream until soft peaks form when the whisk is removed. Carefully fold
in the melted chocolate until smooth and not streaky.
When the cake has cooled, and while it is still in the tin, spoon the chocolate
mousse on top and level with a palette knife. Cover the cake tin with cling
film and chill in the fridge for a minimum of 4 hours, and preferably
overnight, until the mousse is firm.
To serve, carefully remove the cake from the tin and transfer it to a flat
plate. Dust the top with cocoa powder, then pile the raspberries and
blueberries into the centre. Finish with a light dusting of icing sugar. Cut
into wedges and serve with pouring cream.